covert



2 SHEETSSHEE1 'I.

Patented Jan. 18, 1921.

E. C. COVERT.

APPARATUS FOR FEEDING PULVERtZED FUEL.

APPLICATlON FILED MAY 31, 1919 1,365,663.

TUE 1- 2 f L E. C. COVERT.

APPARATUS FOR FEEDING PULVERIZED FUEL.

APPUCATION HLED MAY 31. I919 1,365,663, Patented Jan. 18, 1921.

2 SHEETSSHEET 2.

f UNITED STATES PATENT OFFICE.

EDSON G. COVERT, 0F AVALON, PENNSYLVANIA, ASSIGNOR TO HEYL & PATTERSON,INQ, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

APPARATUS FOR FEEDIN G PULVERIZED FUEL.

Specification of Letters Patent.

Patented Jan. 18, 1921.

Application filed May 81, 1919. Serial No. 300,881

To all whom it may concern:

Be it known that I EDSON C. Cove, a citizen of the Unitedtates, andresident of Avalon, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Ap aratusfor feeding lulverized Fuel; and do hereby declare the following to be afull, clear and em ct ilescription thereof.

My invention relates to apparatus for fee lug pulverized fuel.

The object of my invention is to provide an ellicicnt and simple meansof supplying fuel and air in the proper proportion that the mixture willbe uniform to the suction side of a fan or circulating medium and toprovide means for the delivery of said fuel and air mixture toa singlefurnace with a number of burners or to a number of furnaces, therebydispensing with a separate fuel storage and feeding device at eachfurnace.

Generally stated I employ a closed pipe circuit beginning at thedischarge of the fan and terminating at'the suction side of the fan. Thepipes composin the circuit are of such size that there Wil be sufiieientof a miniture being retunled to thefan at all times so than the velocityin any path of the c rcuit "will never be below that required to an toovercomethe inability of securing an adjustable speed powerunit tosupply the proper proportion of fuel to the system I 3 employ a variableor adjustable speed motor for aminimum and maximum speed with a numberof equal intermediate speeds, and by means of a bypass piple from thzfpipe circuit adjacent to the disc "ar e side t e fan I am enabled toreleasean give amount of fuel from the pi circuit equal to that fuelbeing supplied b; an adjustable speed motor at its minimum speed. y

In the accompanying drawings, Figure l is a side elevation of myimproved apparatus, one of the furnaces being shown partly in section;Fig. 2 is an enlarged side elevation of'thsupply hopper, the: feeder,fan, etc, the pipe circuit. being broken away and the diaphragm and airvalve operated thereby being shown in section; and. Fig. 3' is it viewof one of the furnaces partly in sectionshowing one of the pipes fordelivering the fuel to the furnace.

the fuel in the mixture in suspension,

circuit. L a e A -,a,ble valve 19 connected by t e rod to the the feederdriven by of said lever is conn ted the Referring to the drawings thenumeral 2 designates a suitable storage-hopper for containing thepulverized fuel. At the discharge end of said hopper is the feedinmechanism 3 which it has not been deemed necessary to illustrate indetail, the same bemg a form of feeding mechanism for which LettersPatent of the United States #11977 99 were issued to me. on the 12th dayof September 1916- Ashunt-wound motor 4 is provided for driving thescrews of the feeder 3.

A suitable fan 5 driven by a motor (not shown) provides the air formixing with the fuel delivered to the suction pi e 6 by the pipe 7, andthe combined air an fuel is forced by said fan through the pi e circuitBmmging a complete circuit wit the air p1 e passes by the pipe 16through the valve 17 to the air pipe 9 where it is a sin combined withthe uel delivered b t e feeder ;3 to be carried by the fan t roughtliepipe circuit. r

A vent 18 is provided for supplyingair to the in the by-pass pi e 14 isasuitlever-arm 21 of the field rheostat 22.. A rod 23 connects said lever21 tii thelever-a'rm 24,

said arm havin the slot 25 'which'enga es the pin 26 on t e hopper 2.The opposite end of the lever 24 is ivot'ally connected at 27to-thenut28 on t e screw-shaft 29. i A

lever 30 has the slot 31 wh'ch engages the pin 32 on thenut 28 and t eopposite and crank 33 connected by the link 4 to the air valve 35.

A diaphr m cham or 36 has the" diaphragm 37 w ich is connected by thelink 38 to the switch arm 39 carrying the Wei ht 40.

.ranch pipes 10 connect with the pipepipe 16 and eventually to the pipep The inner end of theswitch arm 89 w on in 11-0 air to re fiufdre 19always being open when .the lever 21 mg of airi motor tospeed.

neutral position lies between the contacts 41 and 42.

The screw-shaft 29 has the large gear wheel 43 which meshes with thepinion 4-4 on the shaft of the air valve motor 1-5.

In the operation of my improved feeder the circulating tan is firststarted which will continue to circulate the mixture entrapped in thepipe line and at the some time draw in sul'licient new air through pi )e16 and valve 1? to make up for that: mine dispelled through pipe 14 andvalve 19 This the total g through valves 12 in pipes inn that beingexpelled through air esca )in 10 is less tvalve 19 in pipe 14.

The feed motor 4 is then started by closing the knife switch 46 whichcauses current to flow through the fiek rheostat 22 which is shown inminimum speed position, to the motor, causing feed screws in feeder 3 tore Tolve, thereby feeding fuel from the storage hop )er 2 through pi we7 to fan suction pipe 6 w 1en fuel is mixed with the incoming air fromvalve. 17 and pipev 16 and that mixture being returned frompipc circuit8.

The fan will contmue to circulate this mixture through circuit 8. withan amount of fuel and air equal to that fed to the tem by feeder 4 andthrough valve 1? and pipe 16 bein r fed to separator 15.

As it is (esirc'd to place fuel consuming devices 11 in operation valves1:! in branch .pipes 10 are opened by means of chains 13 which causes arush of the fuel mixture in pipe circuit 8 to enter fuel cousumingdeviceI, and also causes a vacuum in pipe 9 thereb causing cliaphragmlii whichis at tachcd to lever 39 to descend making an electric contact at 42causing motor 45 to revolve screw 29 causing feed nut on screw to t'ravcl toward gears;

V 'l'his movement of the nut :28 will act. to move the lever 30 and willopen the air valve 35 to a polnt that will admit sufficient.

As soon in pipe normal to norfuel to as'this point is' 9 and valve 35'and diaphragm nel consuming devices,-

reached. air pressure will againbecome will again ascend causing motor(to-stop. 4 a

'As the air valve 35 was hein r opened in the manner above set forth tielever 24 was 'Inovedand through the'lever rod 23, i of'the fieldrheostatv 22 was moved over causing motor 4 to revolve faster and feeder3; to convey more fuel to pipecirouit, the speedo-f feeder 3 ain] thefuel fed y'same be'nf in, synchrony with the open p it V4235 andai;entering circuit The motor 45 Willflmntiuue to operato'. thertbyausirigrair valve 35" I tip-as additional valves 12 )lace that. goingtogether with umspeed of feeder 3 to open and on pipes In to fuel('(Jllslll'lllllg' devices are opened, until field rhcoatat lever :2lcauses slotted lever Bi to close by-pass valve 19 which ivillinunediatci'v cause svstcui to re-- ad just itself to the newconditions.

The diaphragm valre will ascend making electric contact all causingmotor in to rcvolve in opposite direction. and through gears 44.- and 43revolve screw 29 calming nut 28 to travel a way on drawing causinp valve15 to close and through levers 23 and 24 return handle control ol licldrheostat toward minimum speed position causing motor 4 and Feeder $3 toslow down and feed on amount of fuel equal'to that required for thevolume of air enterinr through valve 35.

'hen pressure. again becomes normal in pipe 9, diaphragm 3.) willdescend breaking electric contact 41 and causing motor 4.3 in site .1.

'lhe placing in operation of additional fuel consuming devices willagain cause dia phragm to descend making electric contact at 42, therebyopening valve 35 and speeding up feeder motor t and the shutting down offuel consulning-devices will make elec tric contact at 41 reversing theoperation.

he arrangement as nl nc described will continue to readjust its lf tdemands, the excess fuel and air mixtur openings 12 to fuelLUllSlP-i-HQ' derices'hcing returned to fan and again circulated throughpipe circuit.

The e will be no fuel and air mixture escape to separator if throughvalve l9 and pipe let until such time as ('l)(.ill'1l0lllll3 of 'Fuelbeing consumed is less than that being fed at minimumspeed of feeder l,when valve 19 through connection 241 and by rcason of position of lever2i on field rheostat 22 :n'itomaticall opens; valve [9, which will againthose a rcai'ljustincnt of apparatus to suit new conditions. The valve,.19 remaining open and an amount. of the fuel and air mixture equal. tothat fed by the minimum groi rig to -se pa ra tor l5v As the valves 12to fuel consuming dellil vice-3 l1 are closed the; diaphragm willcontinue to descend motor 4.5 rotate closing valve through feed screw 28and nut 28 motor 4 sloi v down to its minimum' feed position. v y L RWhen fuel consuming devices are \10 longer-in operation knife switch. 46may be pulledstoppingv motor 4. a

A continual swing of the'fan will draw a snflicient amount ofair-through pipe 16 to make in forthemixture being dispelled through-ppe 1-1 to separator ltiwhich can l .oontin e uhti l fuel mixture'isentirelyelimiin pipe circuit and same contains when fan can be shut downclaim 1 1. In apparatus 'for' feeding fuel, the combination of a storagehopper,

pulverized 1'30 a fan, an endless pine circuit, valve cona continuouspipe circuit, valve controlled trolled outlets from said circuit leadingto connections from said pipe circuit to fuel fuel consuming devices, aby-pass pipe conconsuming' devices, means for delivering neeted to saidpi )e circuit, an automatifuel to said pipe circuit, a variable speedcally operating va ve in said bypass, Said motor operating said feedingmean a by by-pass pipe communicating with said atorpass pipecormnimicating with maid pipe 50 age-hopper, means for supplying air tosaid circuit and with said storapediopmr. an au fan, means forfeedingfuel to said pipe tomatically operating valve in said iymascircuit at the suction side of said fan, and pipe, an air pipeconununicating with said means operated by the vacuum on the one pipecircuit, a fan in said pipe circuit, an

tion side of said fan for automatically con ,air valve on the suctionside of said fain .5, trolling the amount of fuel and air admitted adiaphragm on the auction aide of said to said tan. ian, an electricswitch operated by said 2.111 apparatus for feeding pulverizeddiaphragm. a motor. connectiona lu'tweei'i fuel,the combination of astorage-liopper, a said motor and said air valve, a rheoatat fan, anendless pipe circuit. valve controlled operated by said last namedmotor. and 0a outlets from said pipe circuit to fuel con connectionsbetween said rheosiat and will suniing devices. a by-pasa pipeconiniunicatvariable speed motor \vherch the speed of in; with said pipecircuit and with said the. fuel feedingiineans is varied and the airstorage-hopper. an automatically operating supply to the fan is properlyproportioned.

valve in said by;pasa pipe. means for sup 5. 1n apparatus for feedingpulverized 65 plying air td said fan. means for feeding fuel. thecombination of a atoragwhuppera fuel to said pipe circuit, a diaphragmon continuous pipe circuit. a fuel feedeiu a vathe suction side of saidfan. a valve for conriable speed motor connected to said feeder,trolling the auppl) of air to said fan. a mo- :1 tan in said pipecircuit. a Irv-pa. pipi- -tor operated by the movement of saiddiacommunicating with said pipe circuit and 7 phragm connections betweensaid air valve with said storage-hopper. an autmuaiically and said motorconnections between said operating valve in v aid X-Pilsx pipron lastnamed connections and said fuel teedair intake pipc a valve in saidpipe. a diaing means whereby the fuel and air to the phragni, anelectric motor operated by iln;

pipe circuit is automatically controlled. movement of said diaphragnn cinnartioiis 75 3. In apparatus for t'eodil'ig pulverized between saidmotor and said air valve, and fuel, the combination of a storage-hopper,a means operated by the moveincntoi said air continuous pipe circuit. afan in said cirvalve tori-hangingthespred ol'aaid .hl'lfllllu cuit meansfor feedinp varying amounts of speed motor: whereby the movement of saidfuel to the suction side of said fan, a b vair valve and the variationof speed i said 8' pass pipe communicating with, said pipe feedingdevice takes place sinniltaneously circuit, and with said hopper, meansfor supin testimony \vhereol'. l the said lineal; plying air to theSHQtion side of said fan, t. Cori-arr. have hereunto set my band 40 andmeans for varying the supply of air, EDSON {a o and for simultaneouslyvarying the amount of fuel fed to said pipe circuit. Witnessee:

4. In apiiaratus for feeding pulverized Roar. D.T0'1"IEN, fuel, thecombination of a storage-hopper, JOHN F. VILLA

